1. Technical Field
This disclosure relates to a laser apparatus, an extreme ultraviolet (EUV) light generation system, a method for controlling the laser apparatus, and a method for generating the EUV light.
2. Related Art
In recent years, semiconductor production processes have become capable of producing semiconductor devices with increasingly fine feature sizes, as photolithography has been making rapid progress toward finer fabrication. In the next generation of semiconductor production processes, microfabrication with feature sizes at 60 nm to 45 nm, and further, microfabrication with feature sizes of 32 nm or less will be required. In order to meet the demand for microfabrication at 32 nm or less, for example, an exposure apparatus is expected to be developed, in which an apparatus for generating EUV light at a wavelength of approximately 13 nm is combined with a reduced projection reflective optical system.
Three kinds of systems for generating EUV light have been known in general, which include a Laser Produced Plasma (LPP) type system in which plasma generated by irradiating a target material by a laser beam is used, a Discharge Produced Plasma (DPP) type system in which plasma generated by electric discharge is used, and a Synchrotron Radiation (SR) type system in which orbital radiation is used.